Soldering solution



Patented Jan. 31, 1939 1 5 2 2v UNITED STATES PATENT OFFICE SOLDERING SOLUTION Clete L. Boyle, Detroit, Mich.

No Drawing. Original application April 1, 1936, Serial No. 72,060. Divided and this applica tion March 2, 1938, Serial No. 193,586

4 Claims. (Cl. 148-23) This invention relates to an improved soldering form true chemical solutions in soldering flux flux. solutions and are not properly compatible with The present application forms a division of my the other ingredients used therein. Mineral oils copending application Serial No. 72,060, filed are essentially straight chain hydrocarbons and, 5 April 1, 1936. whether of the paraflin base or asphalt base type, a

Soldering solutions commonly comprise water they resist sulphonation. The mineral oils insolutions of a fiuxing agent such as zinc chloride clude as ingredients many hundreds of difierent and a small percentage of ammonium chloride, organic chemicals, the character and presence of a rust attacking and removing acid such as which depend upon the source of the oil but of 10 muriatlc acid and an oil and grease solvent such these numerous ingredients the naphthenic acid 110 as butyl alcohol, butyl acetate, ethyl methyl ingredients are the only ones that respond to ketone. sulphonation. These napthenic acids are pres- A solvent which I have found to have particuent in mineral oils in very minute quantities varylarly desirable properties is mono butyl ether of ing from .03 to .30 of 1% of the total amount of ethylene or di-ethylene glycol. The ether dethe oil. In many instances sulphonation results it rivatives of ethylene or di-ethylene glycol possess in the formation of mahogany acids as the sulhigh solvent properties, a low evaporation rate, phonated product and these mahogany acids are are only remotely inflammable and are readily not water soluble but are soluble in oil only and miscible in water in substantially all proportions. as such are not usable as wetting agents in aquem Due to the smallness of the crevices and the ous soldering flux solutions. peculiar. irregularities of the metal surfaces upon Sulphonated vegetable oils likewise form a large which the soldering solution is used it is highly class of wetting agents but these form colloidal desirable that the solution employed be one that solutions or emulsions in acid soldering flux sowill thoroughly wet and completely spread over lutions and do not form true chemical solutions metal surfaces to be treated. A commercial use of the character here set forth. Care must also 25 in question is in the fabrication of sheet metal be used as to the character of the water used in automobile bodies. The solution should be the solution because if certain hard waters are capable of spreading and creeping into the cre'vemployed the calcium or magnesium salts are ices and joints thoroughly wetting the surfaces precipitated out, rendering the solution unsatisw and it should remove the rust, oil and grease so factory. so that the fluxing action may be uniformly and Soldering solutions employing wetting agents, p p Carried wherein the solution is an emulsion or colloidal To facilitate the wetting of the surface of the solution have heretofore been suggested but the metal a wetting agent may be employed as one particular soldering solution here described is not of h in re n s in th l i n- This wetting of this class. The soldering solution here sought as agent should so function in the solution that is a true clear solution wherein each of the conafter the metal surface has been properly wetted stituent ingredients is free and unrestricted to the oil solvent in the solution will have free play perform its intended purpose in the solution. to act upon the oil and grease film and he muri- The improved soldering solution here described 40 atic acid will be unrestricted to act freely to reemploys a wetting agent which not only assists 40 move the rust and the scale and the fluxing action to a, maximum extent the dispersion of the other will proceed properly. ingredients over the surface of the metal but Generally speaking there are hundreds of difdoes not hamper in any way such other ingreferent wetting agents but while certain'ones are dients in carrying out their intended function.

5 highly satisfactory in one environment they are This improved soldering solution is one wherein wholly unsatisfactory for use in other environthe activity and mobility of each component of ments. In ordinary laundry procedure soap is solution is vastly increased and promotedas comthe usual wetting agent. Soap functions satispared with the restricted permitted activity of tactorily in a neutral or alkaline solution but is the ingredients in a colloidal solution.

unsuitable as a Wetting agent in an d Soldering The class of aromatic hydrocarbons contains 50 flux solution because of the tendency of the soap many which when sulphonated form wetting to break down with the resulting liberation of the agents which will form true solutions in an acid fatty acids therein, environment, but many of them, such as neo- Sulphonated mineral oils include many well merpin, remain stable only in the presence of known wetting agents but generally these do not weak acids and unfortunately most of these sul- 55 phonated aromatic hydrocarbons tends to precipitate metals, and particularly zinc, out of the solution and in doing so the wetting agent itself is thrown out of solution as a complex insoluble precipitate. However it has been found that certain derivatives of certain nitrogenous hydrocarbons, such as the amino acids of either the aliphatic or the aromatic series, when sulphonated and condensed with alkylating or aralkylating agents, not only form true solutions but serve with unusual effectiveness as wetting agents in acid solutions of either low or high concentration and possess unusually desirable properties as wetting agents in the aqueous acid soldering flux solutions. They do not possess any tendency to precipitate out the metal such as zinc, etc. The amino acids when treated as herein set forth, yield products which possess all those characteristics which make for a successful wetting agent in soldering flux solutions.

To prepare such a wetting agent, a suitable starting amino acid of the aliphatic series is allanine (alpha-amino-propionic acid CH3CH(NH2) COOH) Allanine is sulphonated with oleum (fuming sul- Dhurig acid) to form CHI-l -ooon NH:

This may be referred to as alpha amino alpha sulphonated propionic acid. This product is then condensed with a suitable alkyl or aralkyl agent such as cetyl chloride of benzyl chloride respectively. The products formed from these reactions have the following structures:

s on; s 0311 cni-rs-ooon cm-o-ooon is; 1 1K (5H: (1H,

ylated Aralkylated The first or alkylated product may be called cetyl alpha amino alpha sulphonated propionic acid. The second or aralkylated product may be called benzyl alpha amino alpha sulphonated propionic acid.

Another suitable wetting agent is cetyl 2.4 aniline di-sulphonic acid. This is described in my copending application Serial No. 72,060, flied April 1, 1936, now Patent No. 2,117,649, of which this application forms a division.

Wetting agents such as the two above mentioned function in an acid soldering solution whether of weak or strong concentration to cause the rust attacking acid and the oil and grease solvent to spread to a maximum extent over the surface of the metal thoroughly and completely wetting the same. Not only do they produce this result but they do not inhibit in any way the intended action of the rust removing acid or the action of the rust and grease solvent. On the contrary, they appear to emphasize and augment the action of the other component ingredients of the solution causing them to perform their intended function more thoroughly and effectively.

A very efficient soldering flux with decidedly improved wetting and spreading properties is obtained by the addition of a wetting agent of the above described type as set forth in the following formula:

Wetting agent, such as benzyl-alpha-aminoalpha-sulphonated-propionic acid ounces 3 In the above formula the zinc chloride may be replaced with any product having fiuxing ability. It has been found that when a nitrogenous fiuxing agent such as aniline hydrochloride or acetamide hydrochloride is substituted a smaller proportion of the specific nitrogenous wetting agent is required. The nitrogenous wetting agents specifically cited herein have an unusually desirable affinity for a nitrogenous fluxing agent because of their like character and make a very effective soldering flux solution. Due to their nitrogenous character they are thoroughly compatible and readily miscible with the other ingredients in the solution which are of a nitrogenous derivation. A representative formula might comprise the following formula:

Water gallons Aniline hydrochloride or acetamide hydrochloride pounds 3 Ammonium chloride pounds Muriatic acid 18 gallon Mono butyl ether of ethylene glycol gallon Wetting agent, such as benzyl-alpha aminoalpha-sulphonated-propionic acid ounce 1 These improved fluxes are used in the same manner as ordinary fluxes. It will be found that these new types of fluxes, possessing as they do such improved wetting and spreading ability will reach into the corners and crevices and all irregularities of the surfaces to function in a manner utterly impossible with the regular type of fluxes.

This improved soldering solution is a true, clear, chemical solution as distinguished from a colloidal solution or emulsion. It is stable in acid solutions of widely varying character and strength and does not break down or stratify. It is miscible with water of any character and does not precipitate the calcium or other salts thereof. It does not cause the metals, such as the zinc to precipitate out. It possesses a maximum wetting capacity and increases rather than restricts the intended functioning of the rust attacking acid and the oil solvent ingredients in the solution. It functions compatibly with the nitrogenous fluxing agents specified as they are of a like character.

What I claim is:

1. In a soldering flux preparation, a wetting agent therefor consisting of an alkyl or aralkyl derivative of alpha amino alpha sulphonated propionic acid.

2. A solution to be used for soldering comprising a fluxing agent, a suitable acid, an oil solvent, and a wetting agent consisting of an alkylated or aralkylated amino sulphonated propionic acid.

3. In a soldering flux preparation, benzylalpha-amino-alpha-sulphonated propionic acid as a. wetting agent.

4. In a soldering flux preparation, cetyl-alphaamino-alpha-sulphonated propionic acid as a wetting agent.

- CIEI'E L. BOYLE. 

